Fire preventive device for motion picture apparatus



Nov. 1, 1932. H. H. STERNBERG 1,885,488

FIRE PREVENTIVE DEVICE FOR MOTION PICTURE APPARATUS Filed June 10, 931

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am Z i Patented Nov. 1, 1932 HAROLD H. STERNBERG, OF LOS ANGELES, CALIFORNIA FIRE PREVENTIVE DEVICE FOR MOTION PICTURE APPARATUS Application filed June 10, 1931.

My invention relates to safety attachments for motion picture and analogous apparatus utilizing a combustible film, and its principal object is to provide means for automatically severing a strip of film which may have become ignited while passing through the projecting apparatus, to prevent spreading of fire to the film magazine.

The film to be projected is wound upon a reel and such reel is disposed in a magazine which is usually fire-proof. In the operation of the mechanism in reproducing the record on the film, the latter is unwound from the reel or spool upon which it is originally mounted, and is rewound upon a reel or spool located in a second fire-proof magazine. That portion of the film intermediate the two magazines is susceptible to fire and by reason of the highly combustible character of the film such fire is quickly transmitted to the film contained in the magazine, which often causes serious casualties.

A further object of my invention is to provide a device of the character described adapted for quick attachment to any standard projecting apparatus, so as to equip one or both of the magazines with safety means whereby in an emergency such means are instantly and automatically brought into operation to sever that portion of the film exterior to one or both of the magazines and prevent fire being transmitted to the portion of the film contained in the magazine.

The drawing illustrates a preferred embodiment of my invention. However it is to be understood that in adapting the same to meet different conditions, various changes in the form, proportion, and minor details of construction may be resorted to without departing from the nature of the invention as claimed hereinafter.

The accompanying drawing illustrates an adaptation of the invention to a moving picture mechanism and in said drawing:

Fig. 1 is an elevation of a fragment of a Serial No. 543,346.

motion picture apparatus with portions in section, equipped with my safety device.

Fig. 2 is a horizontal section on the line 22 of Fig. 1, looking in the direction of the arrows and showing the parts of the safety device on an enlarged scale.

Fig. 3 is a longitudinal section 011 the line 8-3 of Fig. 2.

Fig. l is a transverse section on the line H of Fig. 3.

Fig. 5 is an enlarged fragmental perspective view illustrating the connection of my improved device to a projecting machine, the dotted lines indicating the magazine support.

Fig. 6 is a fragmental detailed sectional View of a modified form of the blade operating mechanism.

Corresponding and like parts are referred to in the following description and indicated in the several views of the drawings by like reference characters.

As my safety device may be applied to either or both of the film magazines, a detailed description of one will suffice for a clear understanding thereof. The moving picture apparatus may be of any make or type and usually embodies an upper and a lower magazine of which, for the purpose of illustration, only the upper or take-off magazine 10 is shown, the latter being fire-proof and adapted to receive a reel or spool 11 upon which a film 12 is wound.

The magazine 10 is provided with a lower wall opening of rectangular configuration which is surrounded by an outwardly extending flan e 13, and a similar shaped 1101- low extension 14 is fitted within the magazine opening and ordinarily supports the magazine upon the upper wall 16 of a projecting machine casing 17. Bolts 18 are passed through a flange 19 on the extension 14 and screw into openings 20 provided in the upper wall 16 of the projecting machine casing 17.

My safety device is adapted for location between the projecting casing proper and the magazine 10, and for this purpose the magazine 10 and its supporting extension 14 are removed by unscrewing the bolts 18.

My device consists essentially of a rectangular casing 21 in the form of shell having front and rear side walls 22 and 23 and outer and inner end walls 24 and 25, the upper open end of said casing being closed by a plate 26 seated in a countersink formed in the walls contiguous to said opening. Screws 2'1" are received in suitable openings provided in the upper edge of the casing 21 and serve to hold the plate 26 in position thereon.

The casin 21 is preferably in the form of a metal casting or maybe constructedof other suitable fireproof material.

Formed preferably integral witlrthe cas ing 21 is a baffle plate 28 which extends diagonally downward beyond the lower 111L111 ginal edges of the casing and provides chambers 29 and 30 therein.

A cutting blade 31 is mounted in the upper part of the casing 21 and has sliding engagement with the plate 26 closing the upper-end of said casing, said plate being provided with a transverse gate opening 32 over which sa d blade is adapted to be moved. The bla 1S slightly narrower in cross-section than the mterior cross-sectional of the casin 21 and when; actuated is adapted to pass through a suitable opening between the baiilc plate 28 and the closure plate 26. Thus the upper nd of the battle plate 28 and the closure plate 26 provide bearings for the blade 31.

F or mounting my device in position, assuming the magazine 10 and tl e enocnsion 14 to have been removed from the projecting casing 17 by the withdrawal of the bolts 16, the casing 21 is placed upon the upper wall 16 of the projecting casing with the battle plate 26 extending downward through an opening therein. The bolts 18 are then passed th rough openings in the flange 19 of the extension 14, openings 34 of the casing 21, and are then screwed into the threaded openings 20 in the upper end of the projecting casing 17.

When the device is in the position above described, the free end of the film is first passed over a guide roller 35 in the mag. 1 10, and through the GZZLGllSlOl] 14, is then threaded through anopening 36 in the side wall 22 of the casing so as'to dispose it in alignment with the opening 32 or the plate 26. guide roller 35a in the projecting machine casing 1'7 and through a feeding mechanism and lower take-up magazine not illustrated.

It will be noted that the portion of the film extending through the casing 21 is spaced from the baffle plate 28 in the chamber 29, and after leaving the lower feed roller 35a extends upward in the form of a loop through the opening 33 and into chamber 30 of casing 21. v

The film is then passed over a second The operating mechanism of my invention will now be described.

The end wall 24 of the casing 21 is provided with a tubular extension 38, the bore 39 of which communicates through an opening 40 in said wall with the interior of the chamber 30. Adapted for thrust movement in the bore 39 and end wall opening 40 is a plunger rod 41, to the inner end of which is attached a flange element 42. This flange element 42 is connected to the outer end of the shearing blade 31 which is slidably mounted in the casing 21, and its upper'fiat surface has sliding engagement with the inner surface of the closure plate 26 which. provides a bearing therefor. Likewise, the shearing blade 31 in extended position is held in surface en gagement with the closure plate 26 by the upper end of the battle plate 28.

Pivotally mounted on lugs 43 and 44 on the inner surface of theend wall 24 and contiguous to the opening 40 thereof, are detent arms 45 and 46. These arms adjacent their points of connection. with the lugs 43 and 44 are provided with slots 47 and 43 which are adapted to receive the side edge portions of the flange element 42 carried by the blade 31.

ii. coil spring 49 surrounds the plunger 41 in the bore 39 and has its inner end contacting with the flange element 42, while its outer end surrounds and engages a stud 50 formed on the inner wall 51 of a tubular cap member 52. The cap member 52 is provided adjacent its outer end with an interiorly threaded portion 53 which is adapted for engagement with a threaded part 54 of the tubular extension 38 when said cap member is screwed upon said extension.

The outer ends of the detent arms 45 and 46 are bifurcated to provide slots 56 and the slotted portions are bent outwardly in opposite directions. The detent arms are longitudinally twisted in order to dispose the outer ends, and consequently the slots 56, in horizontal alignment. A fuse 57 having spherical end portions 58 is adapted for reception within the slots 56 of the detent arms 45 and46 and serves to hold the blade 31 in retracted position within the chamber 30. In this connection it may be stated that the plunger rod 41, spring 49, and detent arms 45 and 46 comprise the operating means for the shearing blade 31, while fuse 57 comprises the means for holding the blade in retracted position.

The operating mechanism is set by first extending the plunger rod 41 leftwardly through the bore 39 of the tubular extension 38 so as to dispose the side edges of the flange element 42 within the slots 47 and 48 of the detent arms 45 and '46, after which the fuse 57 is positioned with its ends within the slots 56 in order to hold the blade 31 in set or retracted position. In this position the spherical portions 58 of the fuse rest against the out-turned parts of the arms and 46 and hold said arms in engagement with the flange 42 on the blade 31. The spring 49 is then inserted within the bore 39 of the extension 38 and surrounds the plunger rod 41, the inner end of said spring engaging against the outer face of the flange element 4L2. The cap member 52 is then advanced toward the ex tension 38 with the stud 50 thereof project-- ing within the outer coils of the spring d9. The cap 52 is now rotated on the sion 88, which compresses the spring 19 T ween the stud 50 and the flange element 42., T

11 blade 31 when in set or retracted position a above ind cated is positioned to the left 0 the baille plate 28 and its beveled cutting edg 59 extends diagonally across the casing 21.

With the dev'ce in the position illustrated in Fig. 1 and the fuse 57 connecting the detent arms 45 and 46, the film 12 is shown as passing from the magazine 10 int the pro jecting casing 17 A fire originating in the .1. b projecting casing will ignite the part of the film in the chamber 30 and meltthe fuse 57 thereby releas ng the detent arn s 45 and 46, which will in turn release the plunger rod ll. The plunger rod under the powerful reaction of the spring 49 will force the cutting blade 31 through. chamber 30 and across the film opening 32, thus shearing the film and at the same time sealing the openings leading to he magazine.

In 6 I have illustrated a modified form of blade or knife mechanism in which the casing 21 is provided with an extension 62 having a bore 63, the outer end of said extension being interiorly screw threaded at 6%. A plunger rod 65 extends through the wore 63 and is connected at one end to a fiange 66 on a blade 67. The opposite side edges of the flange 6G engage in notches 68 of the detent members 69 which serve to hold the blade in retracted position. A spring 7 O surrounds the plunger rod 65, and its opposite ends engage the flange 66 and an annular abutment 71 on a tubular cap member 72. The cap member 7 2 is provided with a tubular portion 73 which is adapted to extend through the 2 bore 63 and surrounds the spiral spring 70.

Screw threads 74 are provided on the cap member which engage with interiorly disposed threads 64; on the extension 62 when said cap member is screwed up on said extension to hold the parts in set position.

In the event of fire-originating in the proecting machine casing 17, the tendency of the film is to burn in an upward direction that is to say, in the direction of chamber 80.

When the film is ignited, heat is generated in chamber 30 of casing 21, which melts fuse 57 and releases the blade, The blade when released automatically severs the ignited part of the film from the unexposed part of the film in the magazine and simultaneously the It is obvious that the film shearing means employed in my 1 device quick and positive in operation and not only severs the burning part of the him, b also isolates the magazine from the lire 1n the pro ecting machine he the film while passing 7 to the projecting mechafrom the combustion chambaiile plate 28.

*sble to locate my fire preventive etween the lower part of the project- 17 and a wind-up magazine, in as he blade operating mechanism ca inp.

,erating mechanism may be 1c the blade and hold the in retracted position by forcing the outwardly into engagement with ten ms, thus compressing the spring surroundin the plunger rod.

claim my invention 1. In coinbi, on with a moving picture pro ectin mac including a film maga- 21119., a satiety attache" it comprising: a cas ing adapted to be locked in position between said projecting machine and said magazine; a closure plate for said casing providing an ope 'ug for the passage therethrough of a filnn opening communicating with said machine and said magazine; a blade movable across said openii to sever said film; means for holding said blade in retra ted position; 7

Wifety attachment comsaid projecting ins and said magazine; a plate closia one .id of said casing; a wall a mber and a secondary .id casing, said plate ior the passage of said ellCl magazine through said chamber to id projecting ma said casing across i o i ng said film; means :aid 1 5 cnainoer for holding said blade in non-severing position; and a fusible element associated with said holding means C detachably connected to' providing an openi g communicating andadaptediupon combustion in said primary chamberto release said blade holding means, whereby said blade is moved from said pri mary chamber to said secondary chamber in arnanner to sever the film and close said film passage opening.

3.111 combination with a moving picture projecting machine including a magazine for holding a film, a safety attachment comprising a'casing adapted for position ano attachment between said projecting machine and said magazine; a plate connected to said casing. and having opening p iding communication between said ma zinc and said'projectingmachine; walls forming a film passage chamber and a combustion chamber in said caring; a blade normally heldin inoperative position in said combustion chamber and being adapted for movement across said plate opening tossver said film; means for holding said blade in inoperative position in said combustion chamber; heat responsive means associated rith said bla e holding means adapted upon combust on in said combustion chamber to release said blade holding means; and means ope able upon release of said blade holding means for moving said blade to sever the film.

l. In combination with a moving picture projecting machine including a magazine for holdin film a saret device compri in O 7 A C casing adapted for connection between said magazine and salt p-ro ectn g machine; plate closing the upper part of said casr with said magazine and said projecting machine;

a wall extending downwardly from said oa- 3 end en 'a in said fiance when said blade I: b a

in normal position in said combustion chamber; means detachably connected to said fian e for holding said blade in non-cutting )osition in said combustion chambera cap closing the end of QXLQDSlOll bore; a

spring adapted to be compressed on said rod between said cap and said blade flange; and a fuse associated with said blade holding means and adapted upon combustion in said combustion chamber to melt so to. release said blade holding means whereby said blade is projected by said spring across said film passage chamber to sever said film and isolate said film passage chamber from said film magazine;

5. A combination as set forth inclaim'el in which saidcap is adjustable on said casing extension to regulate the tension of said spring.

6. A combination as set forth in claim 4 in which said wall is formed integral with said casing and isolates the film passing through said film passage chamber from said combustionchamber.

7. In combination with a moving picture projecting machine including a magazine for holding film, a safety device comprising: a casing connected between said projecting machine and said magazine; a plate closing the upper part of said casing having a film pasopening therethrough communicating with said film magazine and an opening in the top of said projecting machine; Walls forming a combustion chamber and afilm passage chamber in said casing, one of said walls extending downwardly from said cas ing through said opening in the top of said projecting machine; a blade slidable from' said combustion chamber across said film' passage opening to said film passage chamber; a flange depending from said blade; an extension on said casing having a bore communicating with said combustion chamber; a cap mounted on the end of said extension; plu rod slidably mounted in said bore; a spring surrounding said plunger rod between said cap and said blade ilange; a pair of arms pivotally mounted on a wall of said casing contiguous to said bore opening said arms having notches "for receiving opposite edge por" film and isolate said film passage chamber from said magazine. a r

8. n combination with a motion picture projecting machine including a magazine for holding film, a safety device comprising: a casing adapted for position between said magazine and said projecting machine, said having a film passage communicating respectively with said magazineand said proecting ma hine; walls forming a combustion chamber and a film passage chamber in said casing, said combustion chamber communicating with said projecting machine through an opening in the upper wall thereof; a blade normally disposedin said combustion chamher and operable to move across said film.

passage to said film passa e chamber; an extension on said casing 'providmg'a bore communicating at one end With said combustion chamber; a. cap on said extension closing the other end of said bore; a plunger rod in said bore having one end engaging said blade; a pair of arms pivotally mounted in said casing and having notches therein adapted to receive edge portions of said blade when said blade is in non-severing position in said combustion chamber; heat responsive means for holding said arms in engagement with said blade; and a spring surrounding said plunger rod between said cap and said blade flange, said spring bein put under compression by the engagement of said arms with said blade and said heat responsive means being adapted upon combustion in said combustion chamber to release said. arms, whereby said spring is caused to expand and project said blade across said film passage and isolate said film passage chamber from said magazine.

9. In combination with a moving picture projecting machine including a film holding magazine, a safety mechanism comprising: a casing adapted for position between said magazine and said projecting machine, said casing having a film passage in its upper end communicatin respectively with said magazine and said prcj ectin g machine walls form ing a combustion chamber in said casing communicating with the interior of said projecting machine, said walls also defining a film passage chamber communicating with said magazine through said passage in said casing; a blade movable from said combustion chamber to said film passage chamber; a plunger rod in said casing connected at one end to said blade; a spring surrounding said plunger rod and being put under compression when said blade is in non-severing position in said combustion chamber; heat responsive means for holding said blade in nonsevering position, said means holding said spring compressed, and said heat responsive means being adapted upon combustion in said combustion chamber to release said spring, whereby said blade is projected across said film passage and isolates said film passage chamber from said magazine.

10. In combination with a moving picture projecting machine including magazine for holding a film, a safety mechanism comprising: a hollow casing adapted for detachable connection between said projecting machine and said magazine; a plate closing the upper part of said casing and having an opening therein for the passage of film from said magazine to said projecting machine; a wall extending from said casing to a position interiorly of said projecting machine, said wall dividing said casing into a. primary and a secondary chamber: a blade movable across said plate opening from said primary chamher to said secondary chamber; an extension on said casing having a bore communicating with said primary chamber; a plunger rod movable in said bore; a flange on said blade to which said plunger rod is attached; a cap having threaded engagement with the end of said extension; a pair of arms pivotally mounted in said casing and having notches for the reception of said blade flange; a coil spring surrounding said plunger rod between said cap and said flange; and a fuse connecting the outer ends of said arms, said fuse being adapted upon combustion in said primary chamber to melt and release said arms, whereby the tension of said spring will project said blade across said plate opening to sever said film and seal said secondary chamber from said magazine.

11. In combination with a moving picture projecting machine including a film holding magazine, a safety mechanism comprising: a casing detachably connected to said projecting machine and said magazine; a plate closing the upper part of said casing and having a film passage therein; a wall in said casing forming primary and secondary chambers therein; a blade slidable in said casing across said film passage from said primary chambar to said secondary chamber; a flange on said blade; an extension on said casing having a bore communicating with said primary chamber; a pair of lugs on a wall of said casing; arms pivotally mounted on said lugs and having notches normally receiving the edge portions of said flange; a fuse connecting the outer ends of said arms for holding said blade in position in said primary chamher; a cap threaded on said extension; a plunger rod slidably mounted in said bore and having its inner end connected to said blade flange; and a coil spring normally held under compression on said plunger rod between said cap and said flange, said coil spring being adapted to move said blade across said film passage to sever said film when said fuse is melted by combustion in said combustion chamber.

12. A safety mechanism for a standard projecting machine and film magazine, comprising: a casing adapted for attachment between the upper part of said projecting machine and the lower part of said film maga- Zine; walls forming a film passage in said casing, said passage communicating with the interior of said projecting machine and said magazine; a depending wall on said casing providing a combustion chamber and a film passage chamber therein, said combustion chamber communicating through an opening in said projecting machine with the interior thereof, and said film passage chamber communicating with said magazine through said film passage; blade movable from said combustion chamber across said film passage to said film passage chamber; heat responsive means for holding said blade in non-severing position in said combustion chamber; proj ecting means for projecting said blade from said combustion chamber across said film v passage to said film passage chamber; and

means adapted upon combustion in said combustion chamber to release said blade holding means so that said blade will be projected across said film passage to sever said film and isolate said film passage chamber from said film magazine.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 1st day of June, 1931.

HAROLD H. STERNBERG. 

